In one of the toughest ads yet of the cycle, former Rep. Gabrielle Giffords' gun control group is up with a new spot connecting a House candidate's policies to the actions of a murderous stalker.

The ad will it air in Giffords' former district around Tucson, where one of the country's most competitive House races is taking place. Giffords' group, Americans for Responsible Solutions, is supporting her former top aide, Democratic Rep. Ron Barber, in his rematch against Republican Martha McSally.

In the spot, a tearful Tucson mother described explained how a rejected suitor shot her daughter and her husband. "He threatened her before," the woman said in tears. "I knew, I just knew."

"Martha McSally opposes making it harder for stalkers to get a gun," a female narrator added.

www.youtube.com/watch?v=9Zf3IdKEawY&feature=youtu.be

The ad is supported by a six-figure media buy — a sizable sum in the relatively inexpensive Tucson television market.